Abstract— In this study, we introduce a new soft biomimetic optical tactile sensor based on the working principle of shallow mechanoreceptors: the “TacTipBio.” The primary sensing unit comprises a sharp tip surrounded by four cover tips that when subjected to an external force emphasize the applied direction and contact location, for high-resolution imaging by an internal camera. This design leads to computationally efficient reconstruction of 3D external forces along with contact geometry, localization and depth, by utilizing an analytic tactile model based on dynamic friction and internal pressure. Indentation and press-and-shear tests confirmed this mechanism, with submm location and indentation errors, and normal and shear force time series that match measured quantities. The sensor design opens up a new type of high-resolution optical tactile sensor benefiting from the mechanical processing in the skin.